TY - JOUR A1 - Lamatsch, D. K. A1 - Trifonov, V. A1 - Schories, S. A1 - Epplen, J. T. A1 - Schmid, M. A1 - Schartl, M. T1 - Isolation of a Cancer-Associated Microchromosome in the Sperm-Dependent Parthenogen Poecilia formosa JF - Cytogenetic and Genome Research N2 - In the asexual all-female fish species Poecilia formosa, the Amazon molly, supernumerary chromosomes have frequently been found in both laboratory-reared and wild-caught individuals. While wild-caught individuals with B chromosomes are phenotypically indifferent from conspecifics, individuals carrying B chromosomes from recent introgression events in the laboratory show phenotypic changes. Former analyses showed that the expression of a pigment cell locus is associated with the presence of these B chromosomes. In addition, they contain a so far unidentified locus that confers a higher susceptibility to tumor formation in the presence of pigmentation pattern. Isolation by microdissection and hybridization to metaphase chromosomes revealed that they contain one or several sequences with similarity to a highly repetitive pericentromeric and subtelomeric sequence in A chromosomes. Isolation of one particular sequence by AFLP showed that the B chromosomes contain at least 1 copy of an A-chromosomal region which is highly conserved in the whole genus Poecilia, i.e. more than 5 million years old. We propose it to be a single copy sequence. KW - paternal introgression KW - AFLP KW - asexual reproduction KW - B chromosomes KW - gynogenesis KW - microdissection KW - telomeres Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196785 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 135 IS - 2 ER - TY - JOUR A1 - Camacho, J.P.M. A1 - Schmid, M. A1 - Cabrero, J. T1 - B Chromosomes and Sex in Animals JF - Sexual Development N2 - Supernumerary (B) chromosomes are dispensable elements found in many eukaryote genomes in addition to standard (A) chromosomes. In many respects, B chromosomes resemble sex chromosomes, so that a common ancestry for them has frequently been suggested. For instance, B chromosomes in grasshoppers, and other insects, show a pycnotic cycle of condensation-decondensation during meiosis remarkably similar to that of the X chromosome. In some cases, B chromosome size is even very similar to that of the X chromosome. These resemblances have led to suggest the X as the B ancestor in many cases. In addition, sex chromosome origin from B chromosomes has also been suggested. In this article, we review the existing evidence for both evolutionary pathways, as well as sex differences for B frequency at adult and embryo progeny levels, B chromosome effects or B chromosome transmission. In addition, we review cases found in the literature showing sex-ratio distortion associated with B chromosome presence, the most extreme case being the paternal sex ratio (PSR) chromosomes in some Hymenoptera. We finally analyse the possibility of B chromosome regularisation within the host genome and, as a consequence of it, whether B chromosomes can become regular members of the host genome. KW - A chromosomes KW - B chromosomes KW - sex ratio KW - X chromosome Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196321 SN - 1661-5425 SN - 1661-5433 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 5 IS - 3 ER - TY - JOUR A1 - Heinrich, T. A1 - Nanda, I. A1 - Rehn, M. A1 - Zollner, U. A1 - Frieauff, E. A1 - Wirbelauer, J. A1 - Grimm, T. A1 - Schmid, M. T1 - Live-Born Trisomy 22: Patient Report and Review JF - Molecular Syndromology N2 - Trisomy 22 is a common trisomy in spontaneous abortions. In contrast, live-born trisomy 22 is rarely seen due to severe organ malformations associated with this condition. Here, we report on a male infant with complete, non-mosaic trisomy 22 born at 35 + 5 weeks via caesarean section. Peripheral blood lymphocytes and fibroblasts showed an additional chromosome 22 in all metaphases analyzed (47,XY,+22). In addition, array CGH confirmed complete trisomy 22. The patient’s clinical features included dolichocephalus, hypertelorism, flattened nasal bridge, dysplastic ears with preauricular sinuses and tags, medial cleft palate, anal atresia, and coronary hypospadias with scrotum bipartitum. Essential treatment was implemented in close coordination with the parents. The child died 29 days after birth due to respiratory insufficiency and deterioration of renal function. Our patient’s history complements other reports illustrating that children with complete trisomy 22 may survive until birth and beyond. KW - chromosomal abnormality KW - live-born KW - non-mosaic KW - trisomy 22 Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196535 SN - 1661-8769 SN - 1661-8777 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 3 IS - 6 ER - TY - JOUR A1 - Röder, G. A1 - Steinlein, C. A1 - Schmid, M. A1 - Linsenmair, Karl Eduard T1 - Karyotype and chromosome banding in the Turkish desert woodlouse Desertellio elongatus (Crustacea, Isopoda, Oniscidea) N2 - The karyotype of D. elongatus was investigated by means of C-banding, silver staining, and mithramycinand quinacrine fluorescent staining. The diploid chromosome number is 2n = 50. C-banding shows pericentromerically localized constitutive heterochromatin in every chromosome. Two of the chromosome pairs carry two telomeric nucleolus organizer regions each. No heteromorphic sex chromosomes were found. KW - Karyotype; chromosome banding; Desertellio elongatus; Crustacea; Isopoda; Oniscidea Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30989 ER - TY - CHAP A1 - Schartl, Manfred A1 - Erbelding-Denk, C. A1 - Hölter, S. A1 - Nanda, I. A1 - Schmid, M. A1 - Schröder, J. H. A1 - Epplen, J. T. T1 - High mating success of low rank males in Limia perugiae (Pisces: Poeciliidae) as determined by DNA-fingerprinting N2 - Hierarchical structures among male individuals in a population are frequently reflected in differences in aggressive and reproductive behaviour and access to the females. In general social dominance requires large investments which in turn may have to be compensated for by high reproductive success. However, this hypothesis has so far only been sufficiently tested in small mating groups due to the difficulties of determining paternity by classical methods using non-molecular markers. DNA fingerprinting overcomes these problems offering the possibility to determine genetic relationships and mating patterns within larger groups. Using this approach we have recently shown (Schartl et al., 1993) that in the poeciliid fish Limia perugiae in small mating groups the dominant male has 100% mating success, while in larger groups its contribution to the offspring unexpectedly drops to zero. The reproductive failure under such social conditions is explained by the inability of the ex-male to protect all the females simultaneously against mating attempts of his numerous subordinate competitors. KW - DNS KW - Fingerprint-Verfahren KW - Lebendgebärende Zahnkarpfen Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-87132 ER - TY - JOUR A1 - Leikam, C A1 - Hufnagel, AL A1 - Otto, C A1 - Murphy, DJ A1 - Mühling, B A1 - Kneitz, S A1 - Nanda, I A1 - Schmid, M A1 - Wagner, TU A1 - Haferkamp, S A1 - Bröcker, E-B A1 - Schartl, M A1 - Meierjohann, S T1 - In vitro evidence for senescent multinucleated melanocytes as a source for tumor-initiating cells JF - Cell Death and Disease N2 - Oncogenic signaling in melanocytes results in oncogene-induced senescence (OIS), a stable cell-cycle arrest frequently characterized by a bi-or multinuclear phenotype that is considered as a barrier to cancer progression. However, the long-sustained conviction that senescence is a truly irreversible process has recently been challenged. Still, it is not known whether cells driven into OIS can progress to cancer and thereby pose a potential threat. Here, we show that prolonged expression of the melanoma oncogene N-RAS\(^{61K}\) in pigment cells overcomes OIS by triggering the emergence of tumor-initiating mononucleated stem-like cells from senescent cells. This progeny is dedifferentiated, highly proliferative, anoikis-resistant and induces fast growing, metastatic tumors. Our data describe that differentiated cells, which are driven into senescence by an oncogene, use this senescence state as trigger for tumor transformation, giving rise to highly aggressive tumor-initiating cells. These observations provide the first experimental in vitro evidence for the evasion of OIS on the cellular level and ensuing transformation. KW - reactive oxygen KW - human melanoma KW - MITF KW - cancer KW - skin KW - DNA damage KW - kappa-B KW - oncogene-induced senescence KW - cellular senescence Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148718 VL - 6 IS - e1711 ER -